Continuous flow ultra-centrifugation systems

ABSTRACT

A system is provided that includes a controller, a touch screen having a plurality of control icons, a controlled device, and a single safety sensor. The controller prevents operation of the controlled device without contact by a user of both the single safety sensor and a respective one of the plurality of control icons.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a division of U.S. application Ser. No. 13/462,962filed on May 3, 2012, which is a division of U.S. application Ser. No.12/338,826 filed on Dec. 18, 2008 that issued as U.S. Pat. No. 8,192,343issued on Jun. 5, 2012, which claims the benefit of U.S. ProvisionalApplication Ser. No. 61/008,902 filed Dec. 21, 2007, the contents of allof which are incorporated by reference herein in their entirety.

BACKGROUND

1. Field of the Invention

The present disclosure relates to continuous flow ultra-centrifugationsystems. More particularly, the present disclosure relates to continuousflow ultra-centrifugation systems having an electric drive assembly.

2. Description of Related Art

Centrifugal separation is commonly used to separate a solution into itsconstituent parts based on the density of the constituents. Here, thecentrifugation system creates a centrifugal force field by spinning thesolution containing the constituents to be separated, thus causing theconstituents of higher density to separate from the solution.

Many different styles of centrifugation systems have been used and aretypically classified by, among other things, the flow in the system(e.g., batch or continuous flow) and by the speed by the centrifugation(e.g., ultra-centrifugation).

Common continuous flow ultra-centrifugation systems typically rotate therotor at speeds of more than 60,000 revolutions per minute. Manycontinuous flow ultra-centrifugation systems achieve such speeds usingpneumatic drive systems. However, more recently electrically drivencontinuous flow ultra-centrifugation systems have been developed.

Unfortunately, such prior art continuous flow ultra-centrifugationsystems have several common disadvantages. One common disadvantage isthe size of the system, which often requires significant floor space.Another common disadvantage relates to the failure of the vacuum seals,which are located around the high-speed drive spindle. Yet anothercommon disadvantage relates to the amount of heat generated andtransferred to the solution and its constituents during thecentrifugation process.

Accordingly, there is a need for continuous flow ultra-centrifugationsystems that overcome, alleviate, and/or mitigate one or more of theaforementioned and other deleterious effects of the prior art systems.

SUMMARY

A continuous flow centrifuge system is provided. The system includes arotor, a stator, a stator housing, upper and lower bearing plates, upperand lower bearings, first and second snap rings, and lip seal. The upperbearing rotatably secures a shaft of the rotor in the upper bearingplate. The first snap ring secures the upper bearing to the rotor shaft.The lip seal is over the upper bearing and forms a rotatable seal withthe upper bearing plate. The second snap ring secures the lip seal to aninner diameter of the upper bearing plate. The upper and lower bearingplates are secured to the stator housing so that the rotor isoperatively aligned with the stator.

In some embodiments, the stator housing can include a stator coolingchamber and the system can include a vapor-compression-cooling systemthat pumps a refrigerated coolant into the stator cooling chamber. Thestator cooling chamber and the refrigerated coolant can be sufficient toprevent heating of a heating product within the system by more thanabout 4.0 degrees.

In other embodiments, the lower bearing plate can include a pair ofports and the stator can be positioned in the stator housing so that apower cable and a communication cable are in electrical communicationwith the stator through the pair of ports, respectively.

In still other embodiments, the upper bearing plate can include an innersurface that is sloped in a direction away from the lip seal.

A continuous flow centrifuge system is also provided that includes acontrol interface, a control cabinet, a lift assembly, a drive assembly,and a centrifugation tank assembly. The control cabinet is shaped andconfigured to fit under a horizontal boom of the lift assembly so thatthe control cabinet to occupies substantially the same foot print as thelift assembly.

A system is provided that includes a controller, a touch screen having aplurality of control icons, a controlled device, and a single safetysensor. The controller prevents operation of the controlled devicewithout contact by a user of both the single safety sensor and arespective one of the plurality of control icons.

The above-described and other features and advantages of the presentdisclosure will be appreciated and understood by those skilled in theart from the following detailed description, drawings, and appendedclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is perspective view of an exemplary embodiment of a continuousflow ultra-centrifugation system according to the present disclosure;

FIG. 2 is a perspective view of an exemplary embodiment of a controlcabinet of FIG. 1;

FIG. 3 is an opposite perspective view of the control cabinet of FIG. 2;

FIG. 4 illustrates the control cabinet of FIG. 2 having various coversremoved to illustrate the components therein;

FIG. 5 illustrates the control cabinet of FIG. 3 having various coversremoved to illustrate the components therein;

FIG. 6 is a perspective view of an exemplary embodiment of a vacuumassembly of the control cabinet;

FIG. 7 illustrates an exemplary embodiment of avapor-compression-cooling system of the control cabinet;

FIG. 8 illustrates an exemplary embodiment of an oil filter assembly anda coolant assembly of the control cabinet;

FIG. 9 is a perspective view of a drive assembly and a centrifuge tankassembly according to the present disclosure for use with the system ofFIG. 1;

FIG. 10 is a side view of the drive assembly and centrifuge tankassembly of FIG. 9;

FIG. 11 is a perspective view of the drive assembly of FIG. 1;

FIG. 12 is a perspective view of the drive assembly of FIG. 11 having anupper cover removed;

FIG. 13 is a first partial exploded view of a rotor assembly of thedrive assembly of FIG. 11;

FIG. 14 is a second partial exploded view of the rotor assembly of FIG.13;

FIG. 15 is a sectional view of the rotor assembly of FIG. 13 in anassembled state;

FIG. 16 is a perspective exploded view of a stator assembly of the driveassembly of FIG. 11; and

FIG. 17 is a sectional view of the drive assembly of FIG. 11.

DETAILED DESCRIPTION

Referring to the drawings and in particular to FIG. 1, an exemplaryembodiment of a continuous flow ultra-centrifugation system according tothe present disclosure is shown and is generally referred to byreference numeral 10.

Continuous flow ultra-centrifugation system 10 (hereinafter “system”)includes a control interface 12, a control cabinet 14, a lift assembly18, a drive assembly 20, and a centrifugation tank assembly 22.

Control interface 12 is secured to lift assembly 18 by an arm 16. In theillustrated embodiment, arm 16 is a moveable arm that allows an operatormove the control interface to a desired position with respect to system10. Of course, it is contemplated by the present disclosure for controlinterface 12 to be secured to any component of system 10 such as, butnot limited to, control cabinet 14, drive assembly 20, centrifugationtank assembly 22, and any combinations thereof.

Control interface 12 is in electrical communication with, for example,control cabinet 14, lift assembly 18, and drive assembly 20 to allow theoperator to control the various movements and operations of system 10from one central location. Control interface 12 can be anyhuman-machine-interface (HMI). Preferably, interface 12 is a touchscreen that allows the operator to control the various components ofsystem 10.

Due to various safety regulations, it is common for many controlleddevices, such as system 10, to require two hand control devices apredetermined distance from one another. Typically, both hand controldevices must be activated, indicating that the operator's hands are outof danger from any moving parts, before the control devices activate thecontrolled device. Unfortunately, the use of a touch screen forinterface 12 has made compliance to this safety requirement difficult.

Advantageously, system 10 is configured to provide this desired safetyfeature while maintaining the use of a touch screen as control interface12. Here, system 10 can include a safety sensor 12-1 used in conjunctionwith any one of a plurality of programmed control icons 12-2 (only oneshown) resident on control interface 12. Safety sensor 12-1 ispositioned on a side or rear of control interface 12 so that the safetysensor is a desired distance from programmed control icons 12-2.

In this manner, system 10 is configured so that the operator must,during certain operations, maintain one hand on safety sensor 12-1 andthe other hand on a respective one of the programmed control icons 12-2.Thus, the removal of a hand from any control button 12-1 or icon 12-2will result in system 10 stopping the particular operation. Accordingly,system 10 provides the enhanced ease of use features available whenusing a touch screen interface 12, while ensuring operator safety by wayof safety sensor 12-1.

In the illustrated embodiment, lift assembly 18 is shown as a two-axislift, which is configured to move in at least a vertical direction (x)and a horizontal direction (y). In this manner, lift assembly 18 isconfigured to, under the control of the operator via interface 12, liftand remove drive assembly 20 from tank assembly 22 in a known manner.However, it is also contemplated by the present disclosure for liftassembly 18 to be a single-axis lift or a three-axis lift as desired.

Control cabinet 14 includes a mechanical enclosure 24 and an electricalenclosure 26. A more detailed discussion of control cabinet 14 is madeby way of reference to FIGS. 1-3.

Advantageously, control cabinet 14 is shaped and configured to fit underthe horizontal boom 28 of lift assembly 18. In this manner, the footprint of system 10 can be reduced by allowing control cabinet 14 tooccupy substantially the same foot print as lift assembly 18.

Mechanical enclosure 22 includes an operator access panel 30 and a firstservice access panel 32, while electrical enclosure 26 includes a secondservice access panel 34. Advantageously and as will be described in moredetail below, the various components within control cabinet 14 arepositioned for access via operator access panel 30, first service accesspanel 32, and second service access panel 34 by the appropriatepersonnel.

For example, the components within control cabinet 14 that are commonlyaccessed and used by an operator can easily be accessed via operatoraccess panel 30. Conversely, components within control cabinet 14 thatare commonly accessed and used by service personnel (e.g., mechanics,electricians, engineers, etc) can easily be accessed via first andsecond service access panels 32, 34, respectively.

In addition and as will be described in more detail below, controlcabinet 14 is organized so that the various connectors 36, whichinclude, but are not limited to, fluid connectors, pneumatic connectors,oil connectors, electrical connectors, and communication connectors,generally exit the control cabinet from an upper panel 38 of the controlcabinet.

In some embodiments, one or more connectors 36 can also exit from afront panel 40 of control cabinet 14, where the front panel 40 isadjacent to and faces tank assembly 22.

In this manner, control cabinet 14 is a universal cabinet, namely onethat does not require special configuration as a left-handed orright-handed system. Rather, the only component of system 10 that needbe established in a left or right position is control interface 12,which can easily be secured to the left or right sides of lift assembly18 as needed.

In other embodiments, control cabinet 14 can include one or moreorganization lugs 42 defined on front panel 40. As can be imagined, theuse of system 10 requires numerous conduits, wires, and cables (notshown) that are connected between connectors 36 and the variouscomponents of the system such as, but not limited to, control interface12, lift assembly 18, drive assembly 20, and centrifugation tankassembly 22. Advantageously, lugs 42 allow the operator to maintain theconduits, wires, and cables in a desired and organized location by usingto lugs to secure the conduits, wires, and cables in the desiredlocation.

The internal components of control cabinet 14 are described withreference to FIGS. 4 through 10. FIG. 4 illustrates a view of controlcabinet 14 as accessible from first service access panel 32 and frontpanel 40, while FIG. 5 illustrates a view of the control cabinet asaccessible from operator access panel 30.

Although not illustrated, electrical enclosure 26 includes a pluralityof known electrical controls including, but not limited to, one or moreprogrammable logic controllers (PLC's), one or more relays, one or morecircuit breakers, and other electrical controls. As such, an electricianor controls engineer can access the components in electrical enclosurevia second service access panel 34.

Control cabinet 14 includes a vacuum assembly 44, avapor-compression-cooling system 46, an oil filter assembly 48, and acoolant assembly 50.

Vacuum assembly 44 includes a motor 52 drivingly engaged to a vacuumpump 54. Vacuum assembly 44 is in fluid communication with tank assembly22 via a vacuum hose 56.

Advantageously, vapor-compression-cooling system 46 is in controlcabinet 14 and, thus, can be used to providing cooling to drive assembly20 as is described herein below. Vapor-compression-cooling system 46includes a compressor, an evaporator, an expansion device, and acondenser in fluid communication with one another so that a refrigerantis compressed and expanded in a known manner.

Vapor-compression-cooling system 46 further includes a first coolantreservoir 60 of coolant (FIG. 5) such as, but not limited to, glycol anda first heat exchanger 62 (FIGS. 4 and 7). First heat exchanger 62 is ina heat exchange relationship with the condenser so thatvapor-compression-cooling system 46 is configured to condition orrefrigerate the coolant.

Importantly, control cabinet 14 is configured to pump the refrigeratedcoolant from reservoir 60 to tank assembly 22 and to drive assembly 20,which is described in more detail below.

Oil filter assembly 48 includes an oil reservoir 64 (FIG. 5) and afilter 66 (FIG. 8). Control cabinet 14 is configured to pump the oilfrom reservoir 64 to the upper and lower dampers of tank assembly 22,which is described in more detail below. In some embodiments, controlcabinet 14 is configured to pump the oil from reservoir 64 through aheat exchanger 68 in heat exchange relationship with the refrigeratedcoolant from reservoir 60 to cool the oil.

Coolant assembly 50 includes a second coolant reservoir 70 (FIG. 5)having a coolant such as, but not limited to, water and a heat exchanger72 (FIG. 8). Heat exchanger 72 is in a heat exchange relationship withthe condenser so that vapor-compression-cooling system 46 is configuredto condition or refrigerate the second coolant. Control cabinet 14 isconfigured to pump the coolant from reservoir 70 to the upper and lowerseals of drive assembly 20, which is described in more detail below.

Control cabinet 14 controls the operation of vacuum assembly 44,vapor-compression-cooling system 46, oil filter assembly 48, and coolantassembly 50. Further, control cabinet 14 is in electrical communicationwith interface 12 so that the operator can control each component withinthe control cabinet.

In some embodiments, control cabinet 14 can include a vent 74, shown inFIG. 2, for venting air from within the cabinet to an exterior of thecabinet through a filter (not shown). In certain clean roomapplications, control cabinet 14 can be vented to an exterior of theclean room via a conduit (not shown) in fluid communication with vent74.

Referring now to FIGS. 9 and 10, centrifuge tank assembly 22 isdescribed in more detail with reference thereto. Centrifuge tankassembly 22 includes an upper vibration damper 76, a lower vibrationdamper 78, a centrifuge tank 80, and a centrifuge base 82. Centrifugetank assembly 22 is commercially available from the assignee of thepresent application and thus is not described in detail herein. Rather,drive assembly 20 of the present disclosure is configured to mate withthe known upper vibration damper 76.

Referring now to FIGS. 11 through 17, drive assembly 20 is described inmore detail with reference thereto. Drive assembly 20 includes an upperhousing 90, a rotor assembly 92, and a stator assembly 94.

Upper housing 90 is secured to rotor assembly 92 at an outer housing 140to define an upper seal chamber 96 (FIG. 17) above the rotor assembly.Upper housing 90 having upper seal chamber 96 is commercially availablefrom the assignee of the present application and thus is not describedin detail herein. Rather, drive assembly 20 of the present disclosure isconfigured to mate with the known upper housing 90 having upper sealchamber 96.

In addition, upper housing 90 is secured to rotor assembly 92 at outerhousing 140 to define an air chamber 88 as seen in FIG. 17. For example,upper housing 90 can include an upper seal o-ring 98 (FIGS. 12 and 17)secured between outer housing 140 of rotor assembly 92 and the upperhousing by one or more bolts 100. In this manner, air chamber 88 definesa substantially fluid tight chamber, which mitigates noise fromemanating from drive assembly 20 and prevents spills of cooling fluid,in the event upper seal chamber 96 leaks into air chamber 88.

In some embodiments, it is contemplated for drive assembly 20 to includea sound absorber feature 89 within air chamber 88. For example, it iscontemplated for drive assembly 20 to include a sound absorbing materialsuch as, but not limited to, an open or closed cell foam member withinair chamber 88. In another example, it is contemplated for the soundabsorber feature of drive assembly 20 to include one or more soundbaffles or machined features within air chamber 88 to absorb and/orattenuate noise therein. Further, it is contemplated for the soundabsorber feature of drive assembly 20 to include any combination ofsound absorbing material and the sound attenuating baffles/features.

Coolant assembly 50 pumps coolant from reservoir 70 into upper sealchamber 96 via a first port 102 and returns the coolant to the reservoirvia a second port 104 (FIG. 11). In this manner, coolant assembly 50 isconfigured to cool the upper seal within upper seal chamber 96.

Rotor assembly 92 includes an upper bearing plate 106 and a rotor 108 asseen in FIGS. 13 through 15.

Rotor 108 includes a plurality of magnets 110 disposed therein in aknown manner and a hollow rotor shaft 112. Rotor assembly 92 alsoincludes a lower bearing 114 and an upper bearing 116. Lower bearing 114is secured to shaft 112 by a lower jam nut 118. Upper bearing 116 issealed within upper bearing plate 106 by one or more o-rings 120 (twoshown) and is maintained on shaft 112 by a snap-ring 122 and an upperjam nut 124. Snap-ring 122 is resiliently engaged in a groove (notshown) of shaft 112.

In addition, the upper bearing 116 is sealed from the contents of upperbearing plate 106. For example, rotor assembly 92 can include an o-ring126, a lip seal 128, and an internal snap ring 130. Lip seal 128 forms arotatable seal with shaft 112 over upper jam nut 124. O-ring 126 forms aseal between an inner surface of bearing plate 106 and an outer surfaceof lip seal 128. Snap-ring 130 is resiliently engaged in a groove (notshown) of bearing plate 106.

Lip seal 128 can be made of any material sufficient to withstand theconditions within drive assembly 20. In an exemplary embodiment, lipseal 128 is made of polytetrafluoroethylene (PTFE).

Advantageously, drive assembly 20 does not require rotor assembly 92 tobe held in a vacuum environment, thus allowing more effective cooling ofthe rotor 108. For example, eliminating the vacuum environment from thearea around rotor 108 allows cooling from stator assembly 94, which isdescribed in more detail below, to convectively cool the rotor acrossthe motor gap.

Upper bearing plate 106 includes an inner surface 132 that is sloped ina direction away from lip seal 128. In this manner, any cooling fluidthat may leak into air chamber 88 due to a failure of the seal in upperseal chamber 96 is urged away from lip seal 128 by the force of gravityinto a collection area 134. Thus, upper bearing plate 106 can assist inmaintaining the seal provided by lip seal 128 by ensuring that thecooling fluid does not collect on the lip seal, but rather is moved awayfrom the lip seal towards collection area 134.

Stator assembly 94 includes an outer housing 140, a lower bearing plate142, an inner housing 144, and stator windings 146 as shown in FIGS. 16and 17.

Outer and inner housings 140, 144 define a stator cooling chamber 148therebetween. For example, outer and inner housings 140, 144 can besecured to one another so that a pair of o-rings 150 ensure chamber 148is substantially fluid tight.

Vapor-compression-cooling system 46 pumps refrigerated coolant fromreservoir 60 into stator cooling chamber 148 via a first port 152 andreturns the coolant to the reservoir via a second port 154 (FIG. 11). Inthis manner, cooling system 46 is configured to cool drive assembly 20.As rotor assembly 92 of the present disclosure is not a vacuumenvironment, the cooling of inner housing 144 radiates across the airgap and convectively transfers across the air gap to cool rotor 108.

Without wishing to be bound by any particular theory, it is believedthat the use of refrigerated coolant from reservoir 60 to cool driveassembly 20 is effective to prevent the drive assembly from heatingproduct within system 10. For example, system 10 finds particular use inthe production of viral vaccines, which are commonly manufactured in eggbased media. It has been determined by the present disclosure thatheating of the egg based media, and thus, the product by more than about4.0 degrees Celsius (° C.) is detrimental to the resultant product.

Thus, drive assembly 20 of the present disclosure, which includescooling via circulation of refrigerated coolant through stator coolingchamber 148, is effective at removing sufficient heat generated by thedrive assembly so that the temperature of product flowing through thedrive assembly increases by no more than about 4.0° C. Preferably, driveassembly 20 is effective at removing sufficient heat so that thetemperature of product flowing through the drive assembly increases byno more than about 0.0° C. Most preferably, drive assembly 20 iseffective at removing sufficient heat so that the temperature of productflowing through the drive assembly decreases by up to about 4.0° C. ormore.

Lower bearing 114 of rotor assembly 92 is sealed within lower bearingplate 142 by one or more o-rings 156 (two shown) so that the lowerbearing rests on a resilient member 158.

Lower bearing plate 142 includes a pair of ports 160 for providing apower cable 162 and a communication cable 164 from control cabinet 14 tostator windings 146. More particularly, stator windings 146 are invertedas compared to other motors so that communication ports 160 are formedin lower bearing plate 142 instead of upper bearing plate 106. In thismanner, upper bearing plate 106 does not require ports defined therein.

It should also be noted that the terms “first”, “second”, “third”,“upper”, “lower”, and the like may be used herein to modify variouselements. These modifiers do not imply a spatial, sequential, orhierarchical order to the modified elements unless specifically stated.

While the present disclosure has been described with reference to one ormore exemplary embodiments, it will be understood by those skilled inthe art that various changes may be made and equivalents may besubstituted for elements thereof without departing from the scope of thepresent disclosure. In addition, many modifications may be made to adapta particular situation or material to the teachings of the disclosurewithout departing from the scope thereof. Therefore, it is intended thatthe present disclosure not be limited to the particular embodiment(s)disclosed as the best mode contemplated, but that the disclosure willinclude all embodiments falling within the scope of the appended claims.

What is claimed is:
 1. A system comprising: a controller in a controlcabinet; a touch screen having a plurality of control icons; acontrolled device; and a single safety sensor, said controller beingconfigured to prevent operation of said controlled device withoutcontact by a user of both said single safety sensor and a respective oneof said plurality of control icons.
 2. The system of claim 1, whereinsaid controlled device is comprises one or more portions of a continuousflow centrifuge system.
 3. The continuous flow centrifuge system ofclaim 2, wherein said controlled device comprises one or more of a liftassembly, a drive assembly, a centrifugation tank assembly, said vacuumassembly, said vapor-compression-cooling system, said oil filterassembly, and said coolant assembly.
 4. The continuous flow centrifugesystem of claim 3, wherein said lift assembly has a horizontal boomextending therefrom and said control cabinet is shaped and configured tofit under said horizontal boom so that said control cabinet occupiessubstantially the same foot print as said lift assembly.
 5. Thecontinuous flow centrifuge system of claim 3, wherein said lift assemblyhas a horizontal boom extending therefrom and said control cabinet isshaped and configured to fit under said horizontal boom so that saidcontrol cabinet occupies substantially the same foot print as said liftassembly.
 6. A continuous flow centrifuge system comprising: acontroller in a control cabinet; a touch screen having a plurality ofcontrol icons; a controlled device; and a single safety sensor, saidcontroller being configured to prevent operation of said controlleddevice without contact by a user of both said single safety sensor and arespective one of said plurality of control icons.
 7. The continuousflow centrifuge system of claim 6, wherein said control cabinetcomprises a vacuum assembly, a vapor-compression-cooling system, an oilfilter assembly, and a coolant assembly.
 8. The continuous flowcentrifuge system of claim 7, wherein said controlled device comprisesone or more of a lift assembly, a drive assembly, a centrifugation tankassembly, said vacuum assembly, said vapor-compression-cooling system,said oil filter assembly, and said coolant assembly.
 9. The continuousflow centrifuge system of claim 8, wherein said lift assembly has ahorizontal boom extending therefrom and said control cabinet is shapedand configured to fit under said horizontal boom so that said controlcabinet occupies substantially the same foot print as said liftassembly.
 10. The continuous flow centrifuge system of claim 8, whereinsaid lift assembly has a horizontal boom extending therefrom and saidcontrol cabinet is shaped and configured to fit under said horizontalboom so that said control cabinet occupies substantially the same footprint as said lift assembly.